Although it’s probably already said in bits and pieces, personally I felt that Erika had been a stand-in for the negative aspects of all the other characters. As we know, in the actual massacre, Erika doesn’t appear at all, further confirming the notion that she’s more of a concept than an actual person in the game.
By stand-in, I of course mean that Erika is kind of like Clair in more ways than one. Well, two, actually. Firstly, she’s, in my opinion, a representation of all of the negative aspects of the Ushiromiya family. Secondly, her death seems very similar to Clair’s first death after being laid to rest by Willard. Of course, this could be entirely coincidental.
I noted something particularly interesting in all the novels featuring her and it was that all of the characters’ negative habits and their mutual dislike was largely reduced when compared to the amount directed towards Erika. In fact, the only people that probably just acknowledged her and little else was Kyrie, and the mansion servants. Notably, Kyrie seemed to be the least volatile in her exchanges with her, whereas Natsuhi was understandably in an opposite position.
It’s possible that Bernkastel created Erika by imparting her negative characteristics as a person (the real Erika being probably dead, sadly), coupled with the mutual dislike and vanity of all the Ushiromiya siblings, barring Eva who probably saw her as a useful tool or a kindred spirit in the most strained manner imaginable. This created a character everyone could direct their hatred towards, and it was a very smart move by Ryukishi07 to introduce the character at that time itself, since we got to see much more of the siblings’ interactions than before, where most of them died by the first Twilight in the Witch version of the events at least. On the other hand, the cousins die early since they were significantly fleshed out already in the first four episodes, and we even get to see conflicts similar to those amongst the siblings between the cousins and Erika.
Furthermore, like I said, it was also such a clever move to introduce the character then and there alone since it completely misdirected the readers’ emotions. It made the readers, at least quite a few based on the posts in this thread, direct all their hatred towards her and in the bargain made the readers forget, if only momentarily, that one of the Ushiromiyas, who by this point in the story have become endeared to the readers, is responsible for the murder of almost all of the Rokkenjima inhabitants. Episodes 5 and 6 were kind-of ‘breaks’ from all the twilights and rather featured hints that touch the ‘heart’ of the mystery of the Rokkenjima murders.
Episode 8 was, in my opinion, made to leave at least some semblance of a happy ending to the story, and given that so many while hating Erika also loved her character, it would have been too bad to single her character out. Not to mention the Battle of the Golden Land was probably one of her most dramatic moments where she even tries to murder Dlanor who probably is her only friend in the world. We may also consider Battler to be somewhat endeared to her by the end of Episode 8 but again, that may just be a method of leaving a happy ending.
I personally believe that Ange just liked Erika’s dialogues in Episode 5 and hence quoted her in the trick ending. A lot of evidence may show her to be a shadow Ange, but Erika is inhumanly dedicated to her craft whereas Ange was after a ‘truth’ that satisfied her, not THE truth which Erika had been unabashedly pursuing since the beginning. Also, the ambition between the two differed: Erika wanted to be the Territory Lord of the fragment whereas I doubt Ange had any inclination other than finding evidence to incriminate Eva. It’s also because of the previous point that Ange perseveres as a Witch of Truth while Erika suffers as one.
Of course, this almost entirely built up upon circumstantial evidence, but to conclude I’d say Erika has to be one of the most pathbreaking detectives in any series I’ve read so far.
